What is so fragile that when you say something it breaks?

Does the septum divide the lungs? What is the risk of dying in your sixties? Do rabbits have lungs? What happens to the amount of antibodies in the body after the virus has been destroyed? What role do muscles play in movement? What are the 4 stages of chemical dependency? What is burchette syndrome? Structure of trachea? What is DiGeorge syndrome morbidity rate? Do large breasts cause kyphosis? What does it mean when water turns into blood? Is there such a thing as a anorexic dwarf? What vertebra is least likely to cause a spinal cord injury if fracture? What do you have when you feel something like worm crawling from your neck to your ear in your veins? What three things does the menstrual period contain? What does a toxic sign look like? How many ounces should a bladder hold? Can you damage gold if you burn it? What is it called when your break your radius at the joint? What is a controllable health risk factor?

What is so fragile that when you say something it breaks?